Measuring Intelligence – Vocabulary Review

A set of vocabulary flashcards covering major terms and concepts from the lecture on intelligence measurement, including historical tests, modern assessments, psychometric properties, and debates surrounding IQ testing.

Binet–Simon Scale (1905)

The first systematic, standardized intelligence test designed to measure children’s intellectual abilities using age-graded tasks.

Stanford–Binet Test

Terman’s 1916 revision of the Binet–Simon Scale that introduced the Intelligence Quotient (IQ) concept; now in its 5th edition (SB-5).

SB-5 Factors

Five core areas measured by the modern Stanford–Binet: Fluid Reasoning, Knowledge, Quantitative Reasoning, Visual–Spatial Processing, and Working Memory.

Intelligence Quotient (IQ)

A numerical score representing intelligence; originally a ratio of mental age to chronological age ×100, now norm-referenced with mean 100 and SD 15.

Mental Age

The highest age level of test items a child passes completely, used in early IQ calculations.

Chronological Age

A person’s actual age in years, formerly used as the denominator in the IQ ratio formula.

Norm-Referenced Scoring

Modern IQ scoring method that compares an individual’s performance to a standardized age-based distribution.

Bell Curve

The normal distribution into which IQ scores fall, centered at a mean of 100 with most scores within ±15 points.

• Binet–Simon Scale (1905)

• Goal: "measure the child’s intellectual powers" to identify whether a child was “normal” or “retarded.” (Terminology now considered outdated.)

• True measure of intelligence is an individual performance on complex tasks of memory judgement and comprehension

 

Approach:

• Age-graded test items created for successive age groups.

• Child worked through age sets until failing an entire set.

• "Mental age" = highest age level at which child passed all items.

• Lower mental age than chronological age flagged possible intellectual disability.

• Significance: First systematic, standardized intelligence test

Terman’s Stanford–Binet Revision (1916)

Introduced the Intelligence Quotient (IQ).

Introduce measure of IQ in terms of chronological age and a measured mental age

 

Formula:

IQ = Mental Age

          ———————-   X 100 = 100

Chronological Age           

 

Example: 7-yr-old passing 7-yr items →

7/7x100 = 100

 

7-yr-old passing 8-yr items →7/8 x 100 =  114 (above average).

 

7-yr-old failing 6-yr items →6/6 x 100 =86 (below average).

 

Limitation: Mental-age items capped at 16 ⇒ impossible to test post-16 chronological ages accurately (IQ would artificially decline as denominator rises).

 

Standard Deviation (IQ context)

A statistical unit (15 points) indicating how far an IQ score deviates from the population mean.

Wechsler Adult Intelligence Scale (WAIS-IV)

A widely used adult IQ test yielding a Full-Scale IQ and four index scores: VCI, PRI, WMI, and PSI.

Verbal Comprehension Index (VCI)

WAIS-IV measure of verbal reasoning and knowledge, assessed via subtests like Vocabulary and Similarities.

Include 4 subtests

 

• Similarities: "How are apples and pears alike?"

• Vocabulary: "What is a guitar?"

• Information: "What is the capital of France?"

• Comprehension: "Why are we tried by a jury of our peers?"

Perceptual Reasoning Index (PRI)

WAIS-IV measure of non-verbal and spatial problem solving, using tasks such as Block Design and Matrix Reasoning.

Facility with the spatial perception and visual abstract problem-solving and reflect inductive reasoning skills that not depend heavily and verbal thinking

 

Block Design: replicate 2-D patterns using colored blocks.

 

Matrix Reasoning: choose missing piece respecting row/column rules (e.g., answer = panel 4 in sample).

 

Visual Puzzles: assemble given parts to match target shape (e.g., combination 1 + 3 + 6).

 

Picture Completion: identify missing element (car without wheels, balloon without string).

 

Figure Weights: balance-scale analogical reasoning (e.g., deduce answer "3" using star/pentagon equivalences).

Working Memory Index (WMI)

WAIS-IV measure of short-term storage and manipulation of information, tested with Digit Span and Arithmetic.

Ability to hold in manipulate numbers in working memory and reflect aromatic skills

 

• Digit Span: recall lengthening strings of numbers.

• Arithmetic: mental calculations.

• Letter–Number Sequencing: reorder mixed strings (e.g., "Q1 B3 J2" → "1 2 3 B J Q").

Processing Speed Index (PSI)

WAIS-IV measure of rapid visual scanning and motor coordination, assessed with Symbol Search and Coding.

Measure visual perceptual speed and visual motor coordination skills

 

• Symbol Search: rapid yes/no detection of targets among distractors.

• Coding: transcribe symbol–digit pairs quickly (code-breaker).

• Cancellation: mark all instances of specified targets (e.g., red squares & yellow triangles).

WISC

Wechsler Intelligence Scale for Children, the 7–16-year counterpart of the WAIS.

Block design

Perceptual reasoning

Matrix reasoning

Perceptual Reasoning Index (PRI)

 

WPPSI

Wechsler Preschool and Primary Scale of Intelligence, designed for children under seven.

Visual puzzle

Perceptual Reasoning Index (PRI

Picture completion

Perceptual Reasoning Index (PRI)

Figure weight

Perceptual reasoning

Processing speed index

Symbol search

Coding

Processing speed

Cancellation

Processing speed

Raven’s Progressive Matrices

A culture-fair, non-verbal test of abstract reasoning that requires selecting the missing piece in visual patterns.

Fluid Reasoning

The ability to solve novel problems independent of acquired knowledge; one of the SB-5 factors.

Crystallized Knowledge

Accumulated factual information and vocabulary measured in the SB-5 ‘Knowledge’ factor.

Quantitative Reasoning

Numerical and arithmetic problem-solving ability assessed in the SB-5.

Visual–Spatial Processing

Skill in perceiving, analyzing, and manipulating visual patterns; a factor in the SB-5 and PRI tasks.

Working Memory

Short-term storage and manipulation of information, central to many cognitive tasks and measured in IQ tests.

Reliability (Testing)

The consistency of test scores over time; IQ tests typically show test-retest reliabilities around .85.

Validity (Testing)

The degree to which a test measures what it claims; IQ validity is supported by correlations (.40–.75) with education and job outcomes.

Criterion Validity

Evidence for a test’s accuracy based on correlations with relevant real-world measures like school grades or job performance.

Construct Validity

Extent to which a test truly measures the theoretical trait—in this case, intelligence—rather than related factors such as learned knowledge.

Cultural Bias

Systematic advantage for certain cultural or socioeconomic groups embedded in test items or contexts.

Labeling Effect

The risk that assigning IQ-based categories can stigmatize individuals and influence future performance.

Self-Fulfilling Prophecy

Phenomenon where expectations based on test scores lead individuals to conform to those expectations, impacting achievement.

Learning Disability Detection

Use of IQ and achievement discrepancies to identify students who need specialized educational support.

Giftedness

Exceptionally high intellectual ability often operationalized as an IQ of 130 or above.

Neuropsychological Diagnosis

Application of intelligence batteries to localize cognitive deficits following brain injury or disease.

Objectivity (Testing)

Advantage of standardized administration and scoring that reduces examiner bias compared with subjective judgments.

Non-Verbal Test

Assessment requiring little or no language, such as Raven’s Matrices, aimed at minimizing linguistic and cultural influences.

Wechsler Family of Tests

Generates Full-Scale IQ plus four index scores

Derived from a number of subtests which attempt to measure 4 index scales:

• Verbal comprehension

• Perceptual reasoning

• Working memory

• Processing speed

Wechslers Test age

• WAIS-IV (Wechsler Adult Intelligence Scale, 2008 edition)

 

• WISC (Wechsler Intelligence Scale for Children): ages 7–16 (mirrors WAIS indices).

• WPPSI (Wechsler Preschool & Primary Scale of Intelligence): under 7 yrs

 

 

• Verbal Comprehension Index (VCI)

 

• Similarities: "How are apples and pears alike?"

• Vocabulary: "What is a guitar?"

• Information: "What is the capital of France?"

• Comprehension: "Why are we tried by a jury of our peers?